1. Field of the Invention
This invention relates generally to fuses and, more particularly, to a circuit fabricated in monolithic integrated circuit form that provides protection against both overcurrent and the abrupt application of a voltage to semiconductor devices.
2. Background Art
Electronic circuits are subject to stresses that may damage the semiconductor devices contained therein. These stresses include overvoltage, overcurrent, overtemperature, and the abrupt application of a voltage (hard start). Known overvoltage and overtemperature protection circuits provide varying degrees of protection for their specific areas of concern. However, fuses that protect against overcurrent have historically comprised a material coupled between the power source and circuit that "blows open" when the current exceeds a predetermined amount. This type of fuse is insufficient to protect most semiconductor circuits due to the slow reaction time for the material to "blow open". The semiconductor devices to be protected could be damaged prior to the fuse "blowing".
Thus, a need exists for a fuse capable of being monolithically integrated for providing protection against overcurrent and the abrupt application of a voltage.